1. Field of the Invention
The present invention relates to a fiber optic connector, and specifically to a fiber optic connector that aligns optical fibers mounted in one portion of the connector with optical fibers mounted in another portion of the connector.
2. Description of the Prior Art
Optical fibers are often used for data transmission because of their wide bandwidth and capacity for carrying data in the form of light signals that are unaffected by electromagnetic fields. However, one drawback to the use of optical fibers is the difficulty involved in properly connecting two optical fibers at a connector. Signal losses in the transfer of data across an interface between optical fibers in a connector can cause substantial problems in the transfer of data. If the abutting optical fibers are not properly aligned, a substantial portion of the signal can be lost at the interface. Proper alignment of the optical fibers to minimize signal losses is difficult, because these fibers typically have a diameter comparable to that of a human hair. Any misalignment of the fibers at their interface in the connector can cause light signals transmitted along one optical fiber to be absorbed by cladding that surrounds the second optical fiber. As a result, a substantial portion of the signal conveying data along the optical fibers can be lost, thereby increasing the risk of data loss.
U.S. Pat. No. 4,695,126 shows a connector in which a pair of optical fibers form an angle where their ends meet. This angled interface is used for both reducing reflections and providing mechanical registration of the ends of the abutting optical fibers. However, if one portion of a connector is repeatedly connected to and disconnected from another portion of the connector, means must be provided to enable the repeated and precise alignment of the abutting ends of the optical fibers. This patent does not disclose how such repeated alignment can be accomplished.
Besides aligning the optical fibers in their respective connector parts, a connector must ensure the quality of the interface between the optical fibers. For example, it is desirable to maximize the force of contact at the interface between their abutting ends. Any offsets, incongruities, or other defects occurring at the interface can substantially impair the quality of data transmission through the connector. Further, the need for consistent and accurate alignment of the respective fibers disposed in opposite portions of the connector is substantially complicated by the requirement that different mating connector portions be readily interchangeable with similar connector portions.
In a specific application of this data transmission technology, an optical fiber connector is required that includes a non-disposable member in which one or more generally parallel optical fibers are disposed. This connector member must connect with a complementary disposable member in which a corresponding number of generally parallel optical fibers are mounted. When the connector members are assembled, the optical fibers in the non-disposable member must intimately contact and be substantially aligned with the complementary optical fibers in the disposable member.
Such a connector is intended for use in a hospital environment, to convey data from a sensor to a processing apparatus that is part of a patient monitoring system. The non-disposable member of the connector is associated with a data line connected to the patient monitoring system, and a disposable member of the connector is connected to the sensor, which is inserted into a patient's cardiovascular system. It is contemplated that the monitoring system may be used with a number of patients, e.g., the monitor may stay with a single patient until its intended use is completed and then disconnected from that patient and connected to a second patient through the disposable member of a different connector.
Furthermore, it may be necessary to move a patient connected to a monitoring system from one room to another, and it may be undesirable to move the monitoring system associated with that patient. Accordingly, it may be necessary that the patient be disconnected from the first monitoring system and reconnected to a second monitoring system located in another hospital room.
Realistically, the critical dimensions of the connector members may vary within manufacturing tolerances. It would thus be highly desirable to provide a connector design that enables the optical fibers in the non-disposable member to precisely align with and fully contact the optical fibers and the disposable member at the interface of the connector, with each and every connection, regardless of any small variation in the critical dimensions of the connector members.
Therefore, it is desirable that variations due to manufacturing tolerances in the connector members be accommodated to assure that the optical fibers mounted in the respective non-disposable and disposable members are substantially aligned whenever there is a completed connection. Such alignment cannot rely on the matching of a specific pair of non-disposable and disposable members of the connector. Further, it would be desirable to provide specific alignment means to positively align the optical fibers of the non-disposable member of the connector with those of the disposable member of the connector, both horizontally and vertically, to minimize any offset of the respective optical fibers when the connector is assembled. It would also be desirable to modify the abutting faces of respective optical fibers disposed on opposite sides of the connector interface, to minimize incongruities therein. Such modification should maximize contact of the complementary optical fibers at the interface of the two connector members.
Because of the extreme fragility of the optical fibers, it would be desirable to provide wear surfaces to minimize wear on critical portions of the connector members during the engagement and alignment of the disposable and non-disposable members of the connector. It would further be desirable to provide means for electrically connecting conductors that are mounted in the disposable and non-disposable members of the connector. Disposable and non-disposable members of the connector should lock in a fixed, aligned position when engaged.